Couplers combined with hardening agents



Patented Apr. 14, 1942 I COUPLERS COMBANED WITH HARDENING GENTS Willard 1). Peterson, Rochester, N. Y., assignor to Eastman Kodak Company, Rochester, N. Y., a

corporation of New'Jersey No Drawing. Application November 26.1946, Se-

rial No. 367,215. In Great Britain January 18,

a cam.- (Cl. 95-6) This invention relates to sensitive material for color photography and in particular to'g'elatino silver halide emulsions having couplers incor porated therein.

There have been many proposals for rendering color-forming or coupling compounds non-diffusing in emulsion layers. In processes of multicolor photography in which we have differentially color sensitized emulsions coated on one side of a support" and one or more of the emulsion layers to be retained in the emulsion-layersin which they are incorporated both during 'coating and during processing of the photographic element. Color forming or coupling compounds 'used in processes of this type are those containing a phenolic hydroxyl or reactive methylene group which is capable of reacting with the oxidation product of a primary aromatic a'mino'couplln'g developing agent on photographic development to form dye images in the layers.

,It is an object of this invention to provide sensitive elements for color photography in which the diffusion of the couplers incorporated therein is prevented or reduced to a minimum.

I have found that the diffusion of couplers in gelatin layers may be prevented if a coupler containing an amino group is mixed with the emulsion in the presence of a hardening agent containing at least two carbonyl groups such as aldehyde groups. Hardening agents of this type react both with the amino group of the coupler and with the amino groups of the gelatin to combine the coupler chemically with the gelatin through the medium of the hardening agent. This reaction is similar to that which takes place in the formation of a Schifls base which may be represented as follows:

The amino group reacted with the hardening agent should, in general, be a primary amino l-(p-aminophenyl) -3-methyl-5 -pyrazolone o-hydroxyphenyl thiourea m-aminophenol p- (w-benzoylacetamino) -benz,ene-sulfonamide p -(4 ethoxybenzoylacetamino) benzene sulfonamide The o-hydroxyphenyl thiourea is referred to in British Patent 478,985 and the m-aminophenol contain couplers, it is necessary for'the couplers is listed. in French Patent 836144. Thesulfonamide couplers are referred to in Vittum,'Peterson and Porter U. S. application Serial No.

The hardening agents which may be usediri my process include any organic hardening agent containing two or more carbonyl groups includ ing aldehydic and ketonic groups such as glyoxal, diacetyl and terephthaldehyde. Some of the compounds described in Shepard and Houck U. S.

Patent 2,059,817, granted November 3, 1936,'and

Staud and Briggs U. s. Patent 2,063,351, granted December 8 1936, are suitable. I

Couplers rendered non-diffusing according to my invention may be incorporated either in single layers or in'multi-layer coatings in which three j sensitive silver halide layers are coated on one side of a support. In an element'of this type, 1 (p aminophenyl) -3-methyl-5-pyrazolone can be used as'a -coupler for the green-sensitive layer] to'produce a' magenta dye, m-aminophenol can be used as the coupler for the red-sensitivelayer to produce a blue-green dye and either p-(wbenzoylacetamino) -'benzene-sulfonamide or p- (4-ethoxybenzoylacetamino) -benzene- 'sulfonamide can be used as the coupler for the blue-sensitive layer to produce a yellow dye.

The following examples will serve to illustrate the nature of my invention:

Example 1 To one gram of l-(p-aminophenyl)-3-methy 5-pyrazolone hydrochloride in 50 cc. of water is 'gelatino-silver halide emulsion. Upon exposing and processing in an alkaline developer solution of p-aminodiethylaniline, a magenta dye is generated solely in the lower layer, since there is 'no coupler in the upper layer with which the developer can react. In the absence of the glyoxal, the dye is generated in both layers (indicating diffusion). If the unsubstituted pyrazolone-namely,l-phenyl-3-methyl-5-pyrazolone+- is used with the same concentrationof glyoxal, bad diffusion of the coupler takesplace, with the result that dye 1s.generated in both layers.

Example 2 One gram of m-aminoacetoacetanilide in 40 cc. of 30 per cent aqueous methyl alcohol is treated with 0.4 gram of glyoxal contained in 25 cc. of water. This solution is added to 300 cc. of a silver halide emulsion. The resulting emulsion is coated upon a base, allowed to dry, and is overcoated with a gelatino-silver halide emulsion; Upon exposing and processing this -material in an alkaline developer solution of paminodiethylaniline, a yellow dye is generatedin v the -..coup1er. and .with', gelatin, and producing the lower layer. In the absence or the glyoxal,

dye is generated in both layers.

It will be understood that numerous rnodiflcations may be made in the features of my 0! the appended claims.

I claim:

non-diffusing in gelatino-silver halide emulsions,

v o 1. The method 01' rendering cclorhcoup'lers.

invention described herein and that the inven--' tion is to be taken as limited only'by thelscope 1 s u a wfl acoupler having both an amino 'group' and 'agroup reactive with the developmentproductot a primaryiaromatic amino dehardening agent.

therein a reaction of the gelatin, coupler and 4. A .color-rorming photographic emulsion comprisingagelatino-silver halide layer contain-s ing the reaction product' or a gelatin organic hardening'agent containing at least two'ca'rbonyl veloping ,agent, with the gelatin;

which comprises mixing with the emulsion a coupler containinga primary amino group and a group reactive with the development product of a primary amino developing agent, and. a gelatin organic hardening agent containing at least two carbonyl groups capable :ot reacting 5. a color-forming photographic emulsion comprising a gelatinosiiver halide layer containing the'reaction productoia gelatin organic enin WP. Pq i ail i ms W1 W0 lldh M hyde groups;with az coupler haying .both a primarya'minogroupandia group reactive with the with the coupler and with gelatin, andproducing therein: a reaction oi!v the gelatin, couplerand hardening agent,

2. The method of rendering 'color couplers non-diffusing in which comprises mixing "with the emulsions coupler containing. a primary amino groupfta ndl 'gelatino-silver halide emulsions, j

a group, reactiye'with the deyelopment product,

with v the couplerfand' with gelatin, and, producand hardening agent. 7 l

" oi fa primary amino deyeloping agent and a? gelatin organic hardening agent containing at least two aldehyde groupswcapable oireiacting ingtherein 'a reaction :oi the gelatingcoupleri 337mm method for rendering; i014, time non-diflusing in gelatino-silv er halide emulsions,

which comprises inixingwithg the emulsion a, coupler containing a primary amino group jand a group reactive withjthe development product,

oi aprimar'y aminoldeyeloping agent,and a;

gelatin organic hardeningagfent containing. 'atl developmentTproduct1o! a primary, aromatic,

amino -,developing,asent, and with the gelatin. 7

" 6. A c'olor-tojrming "photographic, emulsion comprising a" gelatino-eilver halide layer contai'nin gth'e reaction product of a diketone with azent'md with: thegelatin. l

,7; A color-i'ormingmxb iotographic emulsion comprising agelatino-silver halidelayer containin'gthe reaction product oi. a gelatin ,organic -'hardening (agent containing at least two car- J S-pyrazoIonefand withithe gelatin.

.cdmprising ,,;a l'reMtinO-sil'ver halide layer con-' 1 I taining the reaction product oi glyoxal with 1- ip-aminophenyl) 3-meth'yl '5 '-fpyrazolone withthe"gelatin.,,f A l :P y aminogroup and a groupreac tire. with the development procl- .uctr of, ,1 a primary arom 'jtic ammo deyeloping 

